From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 578D7C54F51 for ; Wed, 29 Jul 2026 14:12:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 668FA6B008C; Wed, 29 Jul 2026 10:12:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 618ED6B0092; Wed, 29 Jul 2026 10:12:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 52E216B0093; Wed, 29 Jul 2026 10:12:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 3314E6B008C for ; Wed, 29 Jul 2026 10:12:45 -0400 (EDT) Received: from smtpin21.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 98A2AA0654 for ; Wed, 29 Jul 2026 11:42:49 +0000 (UTC) X-FDA: 85041627258.21.D255EFE Received: from out-182.mta1.migadu.com (out-182.mta1.migadu.com [95.215.58.182]) by imf23.hostedemail.com (Postfix) with ESMTP id DE006140004 for ; Wed, 29 Jul 2026 11:42:46 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=vuyvti+8; spf=pass (imf23.hostedemail.com: domain of brendan.jackman@linux.dev designates 95.215.58.182 as permitted sender) smtp.mailfrom=brendan.jackman@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1785325367; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=cBInP0G7hBRjYIAsJ1YuS+3Ld12NRw9QSsq6YAtF1tA=; b=eZ+CXKtpkKoxYTw1pURx3q7hAOqii3A9ToNxXarM5WeDZ+ysHNRZx433W+OwYi0CGT8/oX 6jh9I0UJqX/+W7cFfxCkgEDyo9bKPecZAvxlov7HjKIOYkq8zHcTQ/iUGdjXu0lC4zaKnh 57E2e7Puv+CnHIVdVwX5dN833GAxTqw= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1785325367; b=8i059RO8QyEPjWobqGjBfngtdZm15fb+dpyBv2Pjn6uyPszMcUuxrX9YCCbwABW0LIav+p s3aO3Fp6IFmCxpOfzjkwaAjn27Z8QOytGt/VytbfopLoJTMRmxv+ltkj1BO+rnMKP0BYwX idu6KuOI/85jFfTZ35FzjZPFPwmNtN8= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=vuyvti+8; spf=pass (imf23.hostedemail.com: domain of brendan.jackman@linux.dev designates 95.215.58.182 as permitted sender) smtp.mailfrom=brendan.jackman@linux.dev; dmarc=pass (policy=none) header.from=linux.dev Mime-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1785325360; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cBInP0G7hBRjYIAsJ1YuS+3Ld12NRw9QSsq6YAtF1tA=; b=vuyvti+86m2ZmsFyuTHQDzcvgRE/uB3+UDJi+y3Zr5XD/vSK0aJ8xQfSK0i1AMButhsI1s WXThiwNHX2ilGaSVPW7nttHZDCNZEg+cBlgxGt+AEG7GH74wuOfXncBC/1rrz3o6TzWyW2 iH6yGk5/Ni1vp2Rm44hnjNUv73HzH0E= Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Wed, 29 Jul 2026 11:42:27 +0000 Message-Id: Cc: "Borislav Petkov" , "Dave Hansen" , "Peter Zijlstra" , "Andrew Morton" , "David Hildenbrand" , "Vlastimil Babka" , "Wei Xu" , "Johannes Weiner" , "Zi Yan" , "Lorenzo Stoakes" , , , , "Sumit Garg" , "Will Deacon" , , "Kalyazin, Nikita" , , "Itazuri, Takahiro" , "Andy Lutomirski" , "David Kaplan" , "Thomas Gleixner" , "Yosry Ahmed" , "Patrick Bellasi" , "Reiji Watanabe" , "Sean Christopherson" , "Nikita Kalyazin" Subject: Re: [PATCH v3 01/26] set_memory: add folio_{zap,restore}_direct_map helpers X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: "Brendan Jackman" To: "Mike Rapoport" , "Brendan Jackman" References: <20260726-page_alloc-unmapped-v3-0-6f5729aa9832@google.com> <20260726-page_alloc-unmapped-v3-1-6f5729aa9832@google.com> In-Reply-To: X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: DE006140004 X-Stat-Signature: muxc3dmq4mkq3jusghpqhf51by5dmiwd X-Rspam-User: X-HE-Tag: 1785325366-167407 X-HE-Meta: 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 hb45chCO 7UhoQ2lGqzWzijVjS+1CNNOE1RhaHEOiWWHB/RbFfrpAN0+9N+SaEVjnLW+cHPUfeIQHdaBsoN+lupMsW219gmmSxDns1Gzx8Wyus5Ak3LIXgRPClDx+TE0xGNeVfi8epm98HuZu5zhBASKh4XWGKagmCZj9v7Xq8qmZ60H0sgmGaEsb+8+lOjpoL5SqVVMhIuNGBv2HFNqksOOBB2B9H2sanRyRmBjkR4j0HJNnH0EuFFJ0qwffkPO/xMNkZrxK9ZVF0T3sAKGEY52dhPFgywKhajIel3QwtHXg8Al9TWCTgbdtl+gSBnJqSbQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon Jul 27, 2026 at 10:33 AM UTC, Mike Rapoport wrote: ... >> +#ifdef CONFIG_ARCH_HAS_SET_DIRECT_MAP >> +/** >> + * folio_zap_direct_map - remove a folio from the kernel direct map >> + * @folio: folio to remove from the direct map >> + * >> + * Removes the folio from the kernel direct map and flushes the TLB. T= his may >> + * require splitting huge pages in the direct map, which can fail due t= o memory >> + * allocation. So far, only order-0 folios are supported; this guarant= ees >> + * the unmap is either a complete success or a total failure. >> + * >> + * Return: 0 on success, or a negative error code on failure. >> + */ >> +int folio_zap_direct_map(struct folio *folio) >> +{ >> + struct page *page =3D folio_page(folio, 0); >> + unsigned long addr =3D (unsigned long)page_address(page); >> + int ret; >> + >> + if (folio_test_large(folio) || folio_test_highmem(folio)) >> + return -EINVAL; >> + >> + ret =3D set_direct_map_valid_noflush(page, 1, false); > > There was a discussion about slight differences in the semantics of > set_direct_map_valid() on x86 and on arm64 and that execmem should > apparently switch to set_direct_map_{invalid,default}. > > Maybe for this series it would be better to add a patch that adds numpage= s > to set_direct_map_{invalid,default}_noflush and use > set_direct_map_default_noflush() here? Um, I think probably we need to clean that API up a bit overall, and I think that's probably best handled as a separate patchset? I think with the API as it currently is, the current usage is correct in this patchset, and I'm a bit reluctant to grow this patchset any further (and I didn't want to block v3 on yet another preparatory series, but potentially blocking v4 on one might make sense). > And maybe also pick another Nikita's patch [2] that makes set_direct_map_= * > to take address? I deliberately omitted that, I don't think it's a good idea: https://lore.kernel.org/all/DJJ2QJQQ73CM.2WHKW4AT6QT1D@linux.dev/ (If we do want to change the API we could use PFNs as I mentioned in the last message of that thread, but I don't see any need to change that API).